One of the problems in evaluating outcomes of rehabilitation therapy in general and cancer rehabilitation in particular, has been the lack of valid and reliable measures of outcome. The proposed study addresses itself to only one aspect of rehabilitation--physical functioning. The index of Activities of Daily Living (ADL) has traditionally been used as the measure of physical function. Despite its widespread use, the ADL suffers from several well recognized conceptual and methodological problems. Its numerous versions in use put to question the unity of the concept of overall physical function on which the ADL is based. The various ways in which overall ADL scores are arrived at raise questions about their methodological soundness. The proposed study is an attempt to resolve some of these issues. It aims at clarifying the concept of physical functioning, validating the unity of this concept and developing a rationally based, empirically meaningful scoring system to derive an overall index of physical functioning. It is proposed to carry out two mail surveys of rehabilitation therapists -- psychiatrists, physical therapists, occupational therapists, rehabilitation nurses, social workers and speech pathologists. The sequential surveys draw upon the clinical expertise of these professionals to determine the essential structure of an ADL as well as to develop a scoring system based on the relative importance of specific functions to the overall physical functioning of a cancer patient. The conjoint measurement technique is seen as an especially useful application of an innovative method for the problem under study. The anticipated outcomes of the study are seen to have very significant implications for evaluation of rehabilitation of cancer patients as well as for their clinical monitoring.